In the prior art, as an alternative to standard whip antennas and roof mount mast antennas, automotive concealed window antennas have used silver printed antennas in the vehicle glazing. More recently, embedded wire antennas of quarter or half wavelength have been used in laminated windshields and back windows. Traditionally, antenna windshields have included a wire that is embedded in an interlayer of polyvinyl butyral that is sandwiched between a pair of glass sheets. A galvanized, flat cable connector connected the wire antenna to the vehicle electronic module. Before lamination, one end of the connector was soldered to an end of the antenna wire on the interlayer. The other end of the connector extended from the edge of the laminated glazing to provide a connection in the antenna module. The use of the flat connector generally required the use of relatively expensive prepress equipment to de-air the glass assembly before the window was autoclaved.
Several antenna designs have used coupling feeds to eliminate a connector that extends from the edge of the glass laminate. U.S. Pat. No. 8,077,100 B2 titled “Antenna Connector” from Pilkington discloses an antenna coupling apparatus to transfer the antenna signal from an antenna wire situated inside laminated glass to a connector on an exterior surface of the glass. A portion of the antenna wire is configured in different shapes to form a coupling region. The wire capacitively couples to a conductor surface that is connected to an antenna feeding cable. The coupling region and surface contact forms a two-line transmission line that transfers RF signals received by the antenna to the surface contact. U.S. Patent Application No. US 2010/0266832 A1 titled “Wired Glazing” from Pilkington discloses a rain sensor antenna that uses an inductively coupled coil to couple electrical current from a wire antenna located within the glazing to an electrical device on the exterior of the glazing. Neither of those designs provide an antenna that covers wide bandwidth such as TV VHF bands (47 MHz-240 MHz) and TV UHF band (470 MHz-860 MHz).
With the rapid growth in the demand for vehicle electronics, more and more antennas are being integrated to the vehicle. Particularly at FM and TV frequencies, antenna systems require multiple antennas to provide diversity operation that overcomes multipath and fading effects. In most cases, separate antennas and antenna feeds are used to meet those demands. Therefore, there was a need in the prior art for an antenna, particularly a coupling feed wire antenna, that is capable of supporting multiple frequency bands that serve different applications. Furthermore, there was a need in the prior art for an improved coupling of a wire antenna with multiband characteristics, good performance, and lower cost by eliminating a connector that extends from the edge of the glass laminate.